Water-heater construction.



F. L. o. WADSWORTH. WATER HEATER CONSTRUCTION. APPLICATION FILED OUT. 3, 19 11. 1,Q44,954 Patented Nov. 19, 1912.

4 SHEETS-BR11311- WITNESSES INVENTO gm 9 {07AA122 P. L. O. WADSWORTH. WATER HEATER CONSTRUCTION. APPLICATION 311,21) 001'v a, 1911.

Patented Nov. 19, 1912.

4 SHEETSSHEET 2.

' INVENTOR gm. #wmzz.

WITNESSES 'P. L. 0. WADSWORTH. WATER HEATER CONSTRUCTION. APPLICATION FILED 001 .3, 1911.

Patented Nov. 19, 1912.

4 SHEETS-SHEET 3.

Wu of WITNESSES F. L. O. WADSWORTH. WATER HEATER CONSTRUCTION. APPLIGATION FILED 0013, 1911.

1 ,O44,954, Patented Nov. 19,1912.

' 4 SHBETSSHEET 4.

WITNESSES INVENTOR FRANK L. O. WADSWORTH, F SEWICKLEY, PENNSYLVANIA.

WATER-HEATER CONSTRUCTION.

Specification of Letters Patent.

Application filed October 3, 1911. Serial No. 652,579.

Patented Nov.19, rare.

- To all whom it may concern:

Be it known that I, FRANK L. O. WADS- WORTH, a citizen of the United States, residing at Se-wickley, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in,

Water-Heater Construction, of which the following is a specification.

The invention relates to improvements in instantaneous water heaters, and particularly to the mechanism for controlling the gas valve is eliminated and such valve controlled positively by the thermostatic element to the end that the sticking of the water actuated element in any position will not interfere with the thermostatic control of the fu el supply; the provision of an improved form of controlling mechanism wherein the fuel valve can be opened only when the heater is filled with water and only T when the water is flowing through the heater; and the provision of a simple reli-r able and efiective mechanism forgiving the control as 'above specified.

Certain embodiments of the invention are illustrated in the accompanying drawings, wherein r Figures 1 and 2 are frontand side elevations respectively of an ordinary instantane- I ous water heater, such .as that shown in the patent to Shook, .No. 993,723, with my im- 'provement applied thereto; Fig. 3 is a sec tion on an enlarged scale through my controlling mechanism; Fig. 4 is a section through a modified formof controlling mechanismapplicable-to the heater as shown" in Figs. 1 and 2-; Fig. 5' is asection through a modified formf of controlling mechanism;

Fig. 6 is a. detaiEtv-iew of a modification which may be emp eyed in the structure of Fig. 5; Fig. 7 is a" section through a modified form of controlling mechanism; Fig. '8 is a sectionthrough a modified form of controlling mechanism; and Figs.'9 'and' 10 are still other sections through other forms of controlling mechanisms, the controlling mechanism as shown .in these figures being somewhat aintlogou's.

.of the heater parts ass Referring first to the general alfirangeimenctl',

own in igs. an

2; A is thecasing ofthe heater; B and C are the upper coils of the heater; D is the lower reverse coil connected to the upper coils by means of the pipe E; F are the burners mounted upon the usual burner ring; G is the gas supply pipe; H is the casing of the gas valve for controlling the supply of gas to. the burners; I is a pipe leading from the gas valve to the burner ring; K is the casing, of the water actuated member; and L is the .casing of the thermostatic controlling means.

Referring now to Fig. 3 in connection with Figs. 1 and 2; 1 is the cold water inlet pipe leading from the main into the chamer 2 of the casing K; 3 is a water actuated check valve; and 4c is the outlet from the casing K leading into the, pipe 5, the upper end of which is turned laterally as indicated at 5 in Figs. 1 and 2 and constitutes the cold water inlet to the upper coil B. The outlet from the lower reverse coil C is through the connection 6, which connection leads into the thermostat casing 7, the upper end of such casing 7 being provided with the outlet 7 leading to the service pipes of the house. The upper ends of the thermostat casing 7 and the pipe 5 arec'onnected by means of a pipe 7, so that a circulation may be secured through the coils of the heater,- the connection 6, the thermostat chamber 7 the pipe 7' and the connections 5 when the outlet to the service pipes is closed, such circulation feature being common in the art as shown in the patent to Shook heretofore referred to. A check valve is provided to prevent a flow to the left through the pipe 7 when the outlet 7 is opened, such check valve feature also being old in the art. The thermostatchamber 7 contains a thermostat of anydesired construction, the one shown in the figure being of the ordinary composite type composed of an outertube 8 of 'zinc, cop er or other material having a high we cient of expan sion and an inner tube or rod 9 of porcelain, carbon, nickel, steel, or Invar metal, the latter being secured at its upper end to the adjacent port-ion of the outer element 8 and terminating at its lower end in a knife edge 10 which bears against the thermostat lever 11. The short arm of this thermostat lever is supported on a second'kuife edge 12 secured tothe casting which carries the thermostat chamber and the inelosed thermostatic ele-. ment; and the long arm of said lever passes through a fork 13 secured to the upper end I the stem 18 which passes up through a stuifing box in the upper part of the chamber 2 and terminates ust below the gas valve 15 in a collar 19. A compression spring 20 is interposed between the collar 19 and the lower wall of the gas valve chamber, and

serves to keep both-the check valve 3 and the gas-valve 15 normally closed. Gas is admitted to the upper portion of the gas valve chamber through the fuel supply pipe G and led away from the lower part of the chamber through a pipe I which is in communication with the main burners of the water heater. A second small pipe 21 leads .from theupper portion of this gas valve chamber to the ordinary pilot light which is used for igniting the gas supplied to the mainburners through the pipe 22.-

The operation of' the above described mechanism is as follows: When there is no water or'othe-r liquid in the system, or when the liquid in said system is at rest the check valve 3 will be closed by the pressure of the spring 20, and this spring will likewise hold the gas valve 15 tightly against its seat so that no fuel can pass to the mainmostatically operated parts.

burners no matter what may be the position of the thermostat parts. When water hegins to flow through the system the check valve 3 will necessarily open and the downward movement of this valve will compress the spring 20 drawing the collar 19 away from the-back of the gas valve 15 and leaving it subject only to the control of the ther- If the liquid in the thermostat chamber is below a certain temperature the thermostat lever 11 will be depressed far enough to allow the gas valve 15. to fall away from its seat under the action of gravity alone, and fuel will then flow from the upper part of thegas valve chamber into the lower part and thence' through the pipe I to the main burners where it is ignited by the flame of the pilot light which is constantly supplied with gas through the pipe 21. in the thermostat chamber 7 rises the expansion of the outer positive thermostat element 8.1ifts the knife edge 10, and allows the thermostat lever 11 tobe raised -.by the spring 17 thereby drawing the gas valve 15 against its seat and closin off the flow of fuel from the upper to the ower portion of the gas valve chamber. When thez gas through the heating coils,

As the temperature.

gagement with the thermostat lever; ,When

"the temperature of the liquid in the'thermo- I stat chamber falls again the knife edge 10 will once more depress the thermostatlever 11 allowing the suspended gas valve-to again open, once more turning on the supply of fuel to the main burners, and the above described operations will be repeated as the temperature rises and falls as long as the liquid continues flowin through the heater; and, as will be readily seen the movements of the gas valve under such circumstances will be entirely under the control of the thermostatically actuated mechanism. The gas valve may be made to open and close at any desired temperature by simply varying the adjustment offthe single screw. 16, and by making'the gas valve 15 P j of large diameter, a full" supply of gas can be turned on through thema-in burners 'throu h an exceedingly small movement of the thermostatically controlled parts, and

a very close regulation of temperature of the liquid in the thermostat chamber thereby attained. But as soon as the flow of liquid stops, or imm diately upon the withdrawal of all of the iquid from the system the check valve 3, together with its stem 18 and attached collar19, will belifted by the spring 20 closin the gas valve 15 and preventing any further movement of the latter bythe action of the thermostat parts until water has once more been turned on, and the flowof liquid once more established 1 Oomtmctz'on of Fig .'4.--In the arrangement shown in this figure the control mech,

.anism isplaced at the top of the heater,

the cold water from the main bein led directly to the upper end of the heating coils 11o through a pipe 22. .After passing through the heating receptacle the liquid emerges-f from the lowerportion thereof, enters'the lower end" of the thermostat chamber 23, 4 and passes upward through the same and flows into the pipes 24 and 25 which supply the house system. The inlet passage 22 is in communication through a pipe 26 with the lower side of a diaphragm chamber 27; and the out-let pipe is similarly in chm munication through a passage way 28 "with the upper portion of this diaphragm cham her. The diaphragm 29. which is between these two diaphragm chambers carries at its center 'a recessed metal cap 30 which makes engagement with a loosestem .31 H passing throu h a 'stuflin boxin the. wall of the upper iaphragm cliamben. The gas valve chamber 32 in this construction. is formed in the same casting which carries its the thermostat chamber; and is made large enough to contain all of the thermostatic mechanism, so as to avoid as far as possibie the use ofstufling boxes. Thethermostat is of the usual composite construction comprising an outer expanslble tube 33 and an inner, negative element 34 connected to-- gether at their lower ends; the upper end of the negative element 34 terminating in a knife edge 35 which engages with the thermostat lever 36. The latter is supported at its short arm end by an adjustable screw 3'7 and carries at its outer end a stud 38 and a lead weight 39. The end of the stud 38 bears against the upper surface of a-gas valve 40 which rests loosely on its seat and Y is adapted to open upwardly to admit gas from the main fuel line G to .the line l which leads to the main burners of the heater. Secured to the lower face of the gas valve 40 is a recessed collar 43 and interposed between the flange of this collar and the lower wall of the gas valve chamber is a spring 44 of just suflicient tension to lift the gas valve when the latter is freed from engagement with other parts of the mechanism. In the recess of the collar 43 is located the head of a stem which passes through the lower wall of the gas valve chamber and carries at its lower end a secondflanged head 46, the upper end of which is provided with a leather washer to-seal the opening through which the stem 45 passes when the latter is raised. The lower flange ofthe head 46 is in engagement with the upper end of the stem 31- and interposed between this flange and the adjacent wall of the gas valve chamber is a strong spring 47, the tension of which is suflicient to overcome the tension of the spring 44 and. thus normally hold the gas valve 40 position against its seat.

in its closed The operation of the above described mechanism is as follows: When the system is filled with liquid at rest the pressure on the two sides of the diaphragm 29 is the same, and the tension of the spring 47 will,'

as just described, hold the gas valve.40 closed and prevent any fuel flowing from the supply line to the main burners of the heater But whenever a faucet in the house supply system is opened and the water begins to flow through the heater from the inlet-22 to the outlet 24 the water pressures on the two sides of the diaphragm 29 will be unbalanced by the'resistance to the flow of the liquid through the heating coils and the diaphragm will be forced upward by the greater pressure of the liquid on the inlet side, thus lifting the stems 31 and 45against the pressure of the spring '47, and freeing the gas valve 40 from the restraining influence of this spring. If new the temperature of the water in the thermostat chamher is less than that for which the "thermoknife edge 35 and allows the stud 38 to be brought lnto engagement with the back of the gas valve 40, and the weight 39will then force this gas valve shut against the tension of the spring 44 thereby stopping the flow of fuel to the main burners. When the temperature in the thermostat chamber again falls the contraction of the element 33 lifts the knife edge 15' and with it the thermostat lever 36 and weight 39, freeing the gas valve 40 from the closing pressure of the weight 39 and again allowing it to open under the tension of the spring 4-4. Whenever the water is entirely'withdrawn from the heating system the pressures err the two sides of the diaphragm 29 will be at once equalized,

fand the stem 45 will be depressed by the spring 47 thus positively closing the gas valve 40 and holding it locked against its seat independently of any action of the *other parts until water has oncemore been turned on and the flow of liquid once more established between the inlet pipe 22 and the outlet pipe 24.

- Construction of Fig. 5.-In the construction shown in this figure the cold water from the main passes through the pipe 51 into "the upper end of a cylinder 52, and

- thence through the port 53 and the pipe 54 to the cold water inlet of the heating coils. The water actuated piston member 55 is secured to a stem 56 which passes through a stufiing box in the upper wall of this water cylinder and terminates in a tapered forked flow of water is stopped, or whenever the p shaped cam 57 which embraces the head 58 tapered sides of this forked shaped cam 57 bear against pins 61 on the head 58, and the engagement between these parts acts to von the stem 59 of the gas valve 60. The V close' the gasvalve 60 when the piston58 and the cam 57 are raised. A spring 62' placed behind the gas valve 60 serves to keep said valve normally raised from its seat when its stem is out of engagement with the other actuating portions of the mechanism. The cold water after passing through the heating receptacle emerges from the hot water outlet 63 and enters the thermostat chamber 64, which contains a thermostat of the same general construction as that shown in Figs. 3 and 4. The

terminal knife edge 70 of this thermostat engages with the short arm ofthe thermostat lever 71, and the long arm of said lever carries an adjustable screw'72, which terminates opposite the end of the head 58. The thermostatparts are kept in operative engagement with each other by means of a strong tension spring 73. G is the inlet tothe gas valve and I is the outlet therefrom. The operation of the control mechanism just described is as follows: When no water is flowing through the heater the piston member 55 is raised to the position shown in dotted lines by the action of the spring 75, and in this raised position of the water actuated piston-'membe'r the gas valve 60 is kept closed against the pressure of the spring 62 by the engagement of the tapered cam shaped member 57 with pins 61. When a house service tap or other outlet in the 29 .line supplied with hot water by the heater is o ened the liquid is first withdrawn from behind the piston 55, and the resultant increase of pressure on the front of the piston depresses the latter against the pressure of the spring 75 thus allowing the cold water to flow directly through the port 53 into the feed pipe 54:. This depression of the piston member 55 withdraws the cam shaped member from engagement with the pins 61 3g and allows the gas valve 60 to open under the pressure of' the spring 62, thus allowing fuel to flow through the gas valve chamber into the line I which leads to the main burners of the heater. As the liquid rises in temperature the thermostat by its expan sion will lift the terminal knife edge 70 allowing the thermostat lever 71 to be moved to the right by the tension of the spring 73,

and the continuance of thismovement 49 brings the screw 72 into engagement with the head 58 and closes the gas valve 60 thus shutting off the supply of fuel to the main burners. When the temperature falls again the contraction of the thermostat depresses the terminal knife edge 70, moves the thermostatlever 71 to the left, and freeing the head 58 from engagement with the thermostat lever screw 72, thus allowing the gas valve 10 to again open and again supply fuelto the main burners. This intermittent opening and closing of the gas valve with variations in temperature in the heated liquid will continue as long as water flows through the heater. But as soon as the water is shut ed .the piston member will be raised by the spring 75, and if at this time the gas valve is open it will-be im- V mediately closed by the action of the 'cam shaped member 57, and will beheld closed until a flow of water-is once more started. It-is also evident that the gas valve will be I locked in its closed position whenever the heater 'is emptied of liquid so that no gas can poss bly be turned on;.at such times.

i '65; Construction of Fig. 6. -In the modification of the construction shown in Fig. 6the arrangement of parts is precisely the same. as that shown in Fig. 5, save that the thermostat lever 71 is'moved slightly to the left.

In this construction the cam shaped fork 57 is replaced b a flat plate 80 secured to the upper end 0 the stem 56 of the water actueration of this mechanism will be-readily understood. lVhen the piston member and the head 80 are depressed as shown in Fig. 6 the openingof the toggle joint lever sys 'tem draws the block 83 to the left out of engagement with the collar 85 and allows this collar and the stem 89 of the gasvalve to also move to the left thus opening the fuel valve and admitting gas to the main burners of the heater- When the water actuated piston member and the plate 80 are raised the toggle joint lever system will be closed or shut up thus moving the block 83 to the right into engagement with the collar 35 and closing the gas valve against the pressure of the spring behind the gas valve.

Construction of Fig. 7.-This figure illustratesa very simple and compact arrange-' ment of parts particularly adapted for use on small sized heaters. In this construction the entire control mechanism is placed at the hot wateroutlet of the heater. "The water emerging from this outlet-'which is indicated by the reference character 91enters .ated member, and the head 58 is replaced the thermostat chamber 92, and passes therefrom through a port 93 into the lower end of a cylinder 94 and emerges through apipe 95 leading to the house supply system. The water actuated member 96 is in this case a packed piston member and has ports 97, 97, which, in the lower position of the piston member 96, are closed by a self-adjusting plate valve 98. The stem 99 of the piston member 96 passes through'a s'tnifing box in the upper head of the cylinder and terminates opposite a plate 100 on the lower end of a stem 101. This stem enters the lower part of the gas valve chamber 102'and terminates in a head 103 which engages with a forked collar 104 secured to the lower sideof the gas valve 105. vOn the other. side of saidgas valve there is a second fork carry ing an adjustablescrew 106 which engages a notch in one end of the-lever 107, and. se-' cured to the other end of this leveris a lead welght 108 suiliciently heavy to overbalance.

1 withdraw the stem 113 from es-the weight 108.

the weight of the unrestrained gas valve 105. In the thermostat chamber 92 I place aliquid thermostate composed of two concentric corrugated tubes 109 and 110 hermetically sealed and filled with some liquid having a high coeificient of expansion such as ether, crude oil, or water, the choice of liquid being determined to some extent by the temperature at which it is desired to op- 10 crate. The lower end of the thermostat tubes 109 and 1.10 are secured to the head 111 which closes the lower end of the thermostat box 92, and the upper ends carry a plate 112 which bears against the stem 113, and said stem passes through a stuiiing box in the wall of the gas valve chamber and engages with the lower side of the lever 107. v

The operation of the control mechanism just described is substantially the same as that of the preceding constructions and will be rendered clear by very brief description. Whenno water is flowing the pressures on the two sides of the piston member 96 will be equalized by a slight leakage of liquid 2 through the ports 97, 97 and the piston member will be held in its lowest position by the pressure of the spring 115,which likewise serves to hold the gasvalve 105 in its closed position atsuch times throu h the engagement ofjth'e head 12 with the orked collar 104. As long as no water flows therefrom, or whenever water is entirely withdrawn from the system, the gas valve 105 will remain shut preventing any passage of I 5 fuel through the gas valve chamber 102.

When a flow of water is started by opening an outlet in the pipe 95 the pressure on to of the piston 96 will be reduced, and sai piston will be forced upward against the 40 pressure of the spring 115 simultaneously raising the stem 101 and releasing" the gas valve 105 from the restraining in uence of that spring. The gas valve 105 will then be raised by the counterweight 108 until the arm 107 comes into contact with the thermostat stem 113. This raising of the gas valve to the extent permitted by the position of the stem 113 will allow more or less fuel to flow through the gas valve box from the sup- 5o ply pipe G to thefeed pipe I which leads to the main burners. As water flowing through the thermostat chamber 92- rises in temperature the thermostat elements will expand, raising the stem 113 and with it thewei ht 255 108, allowing the gas valve 105 to falluntil it is seated, thereby cutting 011' the fuel-Suppl to the feed pipe I. be held closed by its own weight, and by the ressure of the fuel ,in the upper portion f th stat elements have contracted suificiently to engagement witlithe'arm 107, and "then the fuel valve 105- will be once more opened and lifted by 'inclosed in The gas valve 105 wi'l e valve box chamber. until the thermo-. the back of'the gas valve 128 and serves to As long as the flout of.-

liquid continues these intermittent movements of the gas valve will be controlled solely by the action of the thermostat parts; but as soon as the flow of liquid is stopped the immediate equalization of the water pressure on the two sides of the piston member 96 will allow the spring 115 to depress said piston member and the stem 101, to the position shown in the figure, and this depression of the stem 101- brings the head 7 103 once more in engagement with the forked collar 104 thereby closing the gas valve 105, the tension of the spring 115 being sufficient to overcome the eflect of the unbalanced component of weight 108. Construction 0] Fig. 8.This figure also illustrates a very simple and compact construction, in which the thermostat control element is of the same general character as that illustrated in Fig. 7. The hot water after passing through 'the heater coil emerges from an outlet 121 and passes through the thermostat chamber 122 and e nters the pipe 123 which communicates with the house supplv system." The thermostat 0 element 123 is of the same construction, as already stated, asthat illustrated in Fig. 7, save that the upper plate 125 isnot per-'v forated :tor the "admission of water to the space within the inner corrugated tube, but oa is made solid and bears at its center against the upper end of a ollow stem l36'which passes downward t rough the gas valve chamber 127 and the as valve .128 and at its lower end is Ithreaded to receive thenut 129 10a and a lock nut 130. Interposed between the upper end of the stem 126 andt-hebottoin of the therm'ostat-chamberis a stiff spring 131 which is normally under com: Y pression. The top of the thermostat chamber is-closed by a flexible dia hragm 132 to the center of which is secure a stem 133 which projects both above and below the diaphragm. The upper end of this stem is threaded to receive a nut 134 which bears upon the top of a compression spring 135 a chamber formed by the cap 136.. The space above 'the/ diaphragm communicates throu h a pipe 137 with a cold water fee pipe 138 which leads from the Water main to the cold water inlet of the heater. The lower portion of the stem 133 passes through the stufling box 139 in the endplate of thether-- most'atelement, continuesgdown through the hollow stem 126, and is threaded atits lower end to receive a leather faced nut 140 which is adapted to engage with the end of a hollow cap 141 which isscrewed to 2 1 5 cover and inclose the parts 129, and 130 and prevent the passage of gasfrom one side to the otherof'thevalve through the opening for the stem 126.

The operation of the mechanism shown 1 30 in Fig. 8 is as follows: When no water is phragm-12 will be reduced by the resistance to the fiow ofthe liquid through the heater coils, and the greaterpressure of the'water on the upper side of said diaphragm will depress it to the positionshown in full linesin Fig. 8, thereby allowing the gas valve 128 to drop away from its seat and permit the fuel to flow from the inlet passage Gr element 124 expands, lifting the plate 125;

v andallowing the stem 126 to be raised by the spring 131 thus closing the gas valve; 12 1 and shutting off the flow of fuel-through the gas valve chamber. The tem eraturebe regulated by nuts l29 and 130,..these being readily adjusted by the removal of the admittin This con rollin "and regulating action of the thermostat 1n shutting off or supplying to the outlet passage 1* which communif cates with the main burners of the heater. As the water in the thermostat chamber 122:

becomes hotter the liquid in the thermostat at which the gas valve completelyc oses can nut 140 and the cap 141. If the tem erature in the thermostat chamber shoul 7 for an a nea-son continue to rise after the gas va 've 128 has closed the subsequent upward movement of theplate 125 will not be li m-. ited' or restrained by the seating of the; valve 128 and the consequent cessation of movement of the-valveparts. When the temperature in the thermostat chamber 122 falls the thermostat element 124 will-shorten again unden the pressure of" the water in the thermostat chamber,'and the plate 125; will, come into contact withthe end of the the Spring. 131 and stem 126 compressin' allowing the gas va vei 128 to open again morefuel to the main burners.

fuel to the mainburnersuwillcontinue-. as

long as water continues to flow through the Uonstruction ofFig. 9..This-figureillustr'ates the-appllcation' of my im rovement' heater. But'as. soon as the flow of water is stopped or whenever the water is.entirel'y withdrawn from ization of pressure on the two sides 0 the diaphragm 132" will permit the spring 135 raise the stem 133 thereby forcing the' gas valve 128,} to its seat and holding it closed-until aiflow of water is once .more

7 set up through the henter 'coilslj to a standard type of the so calle instanhe system the egualv taneous water heater in which the cold water flows from the main-through a pipe 151 into the rear end of a water cylinder 152 containing a piston 153 which is held normally at the lefthand end of the cylinder by means of a compression spring 154. A port 155 leads from the upper part of the water cylinder 152 to a pipe 156 which communicates through the regulating cock 157 with the inlet 158 to the heating receptacle. After passing through this series of heating coils fro-m'the top to the bottom the water emerges from, an outlet 159 and enters a' vertical thermostat chamber 160 which communicates at the .top with a pipe 161 leading to the house supply system. Located in the thermostat chamber 10 is a composite thermostat element, of a construction similar to that illustrated in Figs. 3 and 4, engaging at its lower end with an adjustable screw 162 in-the thermostat lever 163. This thermostat lever 163 carries at the end of its long arm a second adjustingscrew 164 engaglng in turn with a second thermostat lever 165, the longarm of which bears against a collar 166 at the outer end of a stem 167. This stem 167 passes through a stufiing box 168 in the front wall. of the gas valvechamber 169 and terminates at its 1nner end in the gas'valve 170 which se 3.-

rates the two parts of the-gasvalve cham er 169.. r A spring 171 isginterpose'd between the fi'ont wall of the gas valvechamber and the end of the thermostat lever 165 and serves to; keep the thermostat .parts in operative engagement with each other. A second sprin 172 of about half the strength gas valve 170 and the adjacent left hand wall of. the gas valvechamber. The stem 1675s made hollow to receive a second stem.

173fwhich passes through a' stufing box 174 in the gas. valve 170, and terminates in a head 175. spring 176 of about the same istrengtha's the sprlng 171 isinterposed b'etweenthe'had.l75 and-the ca 177 at thev right hand .end ofjthe gas va ve chamber 169., This spring-serves in normally hold the gas valve 176 in -itsrelosed osition "aTglainst the lesser tension of the spring 172;

of the spr ng 171 is interposed between the e piston 153 in the water cylinder 152 bears'against'the inner end of a stem 178 which passes through a. stufiing-box-179 in the frontwallf of the water cylinder and terminatesopposite the end of 'thestem 17 3;

the space in front of thepiston153 to the -pipe 157. v Theoperation .of the mechanism above described is as follows i-When the systemis filled with waterat rest the piston 3' is held in the position shown-in the. figure by.

9f water is started by; ope

I At the frontend of the-water cylinder 152 there is a. smallport180 which leads from the house pipe the pressure on the front side of the piston 153 is reduced by the withdrawal of cold water behind it, thus opening the port 155 and'establishing free communication between the inlet pipe 151 and the cold water feed pipe 156. The for ward movement of the piston 153 brings.

the end of the stem 178 into engagement with the end of the stem'173 and moves this stem and the attached collar 175 to the right compressing the spring 176 and relieving the gas valve 170 from. the restraining action of this spring 176. Unless the temperature in the thermostat chamber 160 is too high the gas valve will now be opened by the action of the spring 172 allowing fuel to flow through the gas valve chamber 179 to the fuel feed pipe G which leads to the main burners in the base of the heater shell. The ignition of the gas at these main burners is accomplished by means of an ordinary pilot light which may be supplied with fuel throughthe independent 00111180- tion' 182. As the flowing water is heated and the temperature in the thermostat chamber 160 increases, the expansion of the outer element lifts the inner negative element allowing the thermbstat lever system to be moved to the left by the pressure of the spring 171. This movement continues until the long end of the thermostat lever 165 comes in contact with the collar 1.66 on. the gas valve stem 167 and forces the gas valve'170 shut; thus cutting off the supply of fuel to the main burners. When the temperature of the liquid in the thermostat chamber 160 falls, the thermostat lever system will be moved to the right by the con traction of the outer thermostat element compressing the spring 171 and leaving the gas valve 170 free to open again under the tension of the spring 172. This opening and closing movement will be continued as the temperature rises and falls until the flow of water through the heater is stopped. As soon as this occurs the equalization of 'p'ressure'on the two sides of the piston 153 allows the latter to be moved to the left by-the action of the spring 154 thus withdrawing the stem 178' from engagement with the stem 173 and bringin the collar 175 once more into contact with the gas valve 170, which will then be forced shut by the pressure ofv the spring .176, and held locked in its cut-ofi position-no matter what may be the movements of the'thermo- 186. When the water is at rest the piston 153 is forced back by the spring 190. The stem 183 is held to the right by the spring 191 bearing against the head 192, and the head 184 engaging with the forks of the collar 185 pulls the gas valve 187 against its seat and prevents any fuel flowing through the gas valve chamber. When the flow of water is started the piston 18$) is moved to the right finally engaging the head 192 and securing the release of the head 18+ from eugagement with the forks of the collar 185, and freeing the gas valve from the locking action of the spring 191, thus allowing it to open under the action of the spring 188. As the temperature of the flowing water rises and falls,'the position of the gas valve 187 i is correspondingly altered as before by the movement of the thermostat lever 165 which engages with the flanged end of the forked collar 184. The lost motion connection between the iston189 and the stem 183 permits the slight amount of movement of the piston due to reactions in the heater to occur without opening the gas valve.

llt will be noted in all of the modifications of the structure as heretofore described, that the fluid actuated member and fuel valve are so connected that when no water is tlo\v ing, or when the liquid is entirely withdrawn from the heating system, the

fuel valve will be held closed and cannot be moved by any action of the thermostat no matter what position the thermostat parts may assume. ther noted that the said connections between the water actuated member and the fuel valve provide for the complete release of the latter from any restraint by the former when the fluid actuated member is moved by It will befurthe flow of liquid through the heater, thus a leaving the fuel valve at such times solely under the control of the thermostat and its connected control mechanism. The latter mechanism is so arranged that it has no direct effect on the opening movements of the fuelvalve, these movements being efi'ected solely by means which act independently of both the Water control mechanism and the temperature control mechanism. The thermostat parts moreover do not act. directly on the valve in closing the latter but act simply to control the movements of -i spring or Weight. which in turn closes the fuel valve when the thermostat permits of this. in consequence of these characteristics of operation the fuel valve of my improved double control mechanism may-be said to be normally open in the sense that it is opened whenever it freeo .from'the restraining influence of the water The elosafter said valve has closed the thermostat parts may go on moving without throwing any strain upon any part of the temperature control niechanism. 'The same statement is true of the movement of the thermostat parts in the opposite direction,that is the direction taken when the temperature is falling and the valve. is being released from the action of the spring or weight which has closed it. Both the openingand the closing movements of said'valve are therefore rendered quick and positive and all delicate balances of opposings springs and the consequent uncertainty and hesitation of movement of the valveparts controlled thereby =-g are thus avoided. a

It is obviousas shown by the various illustrations abovepresentedthat my improvements are capable of embodiment in various detail forms; and that numerous modifications of the mechanical construction may be ,made without departing from .my

invention.

Having thus described my 1nvent1on and illustrated its. use, what I claim as new and 5 desire to secure by Letters Patent is the followinlgz 1. n comblnation 1n an instantaneous water heater, a water actuated means operatedby opening and closing the outlet from the heater, a thermostat, a gas valve yieldingly maintained in open. position when not acted upon externally, means controlled. by the said water actuated means' for maintaining the gas valve yieldingly in closed position when the outlet from the heater is closed and permitting the gas valve to open when the said outlet is open and the temperature of the water is below a predetermined point, and yielding means controlled by the thermostat for closing the gas'valve when the temperature of the water rises above said predeterminedpoint.

I 2. In combination. in an instantaneous water heater, a water actuated means operated by opening and closing the outlet from the heater, a thermostat, a gas valve yield.- ingly maintained in open position when not acted upon externally, means controlled the said water actuated means for maintaining the gas valve yieldingly in closed position when the outlet from the heater is closed and permitting the gas valve to open when thesaid outlet is, 0 en and the temperature of the water is elow a predeterea mined point, and means whereby the valve is permitted to. close. yieldingly when the temperature of the water rises above said predetermined point, the'said yielding closure being under the control of the thermostat.

3. In' combination in an instantaneous water heater, a water actuated means operated by opening and closing the outlet'from the heater, a thermostat, a gas valve yieldingly maintainedin open position when not acted upon by the" therm ostat or th'e water actuated means, mea'p's controlled by the said Water actuated means for maintaining the gas valveyieldingly in closed:positio'nwhen the outlet from the heater is closed andpermitting the gas valve to open when the said outlet is open andthe temperature of the wateris below a predetermined point, and means whereby a yielding closure of the gas valve is secured when thetemperature of the water rises above said predetermined point, the said yielding -closure being-under the control of the thermostat. 4:. In combination in an instantaneous water heater, a water actuated means operated by opening and closing the outlet from the heater, a thermostat, a gas valve yieldingly maintained in open position'when. not

acted u on by the thermostat or the water actuate means, means controlled by the said water actuated means for maintaining the gas valve yieldingly in closed position when the outlet from the heater'is closed and permitting the gas valve to open whenthe said.

outlet lslopen and the temperature of the water is below a predetermined point, and yielding means controlled by the thermostat fo m oving the gas valve to closed position when the water rises above said predetermined point. 7

5. In, combination. in an instantaneous water heater, a water actuated means operatedby opening and closing the outlet from the heater, a thermostat, a gas valve yieldingly maintained in open position when not acted upon by the thermostat or the water actuated means, means controlled by the said water actuated; means for maintaining the gas valve yieldlngly in closed pos1t1on when the outlet from the heater is closed and permitting the gas valve to open when the said outlet is open and the temperature of thewater is below a predetermined point, and a spring, held normally in inoperative position by thev thermostat, but permitted thereby to operate and close the gas valve when the temperature of the water rises above a predetermined point.

6. In combination in an instantaneous water heater having, an'inlet and an outlet, a reciprocatory-water actuated element operated by opening andiclosing the outlet from the heater, a thermostat,- a gas valve, a

,s rin tendin a 0 en the gas valve, a sec- P g g P ond stronger spring tending'to close the gas .valve when the outlet from: the heateroisclosed and the water actuated element is in its rear position, but restrained from acting on the valve to close it when the outlet from the heater is open and the water actuated element is in its forward position, and a third spring also stronger than the first spring and controlled by the thermostat for}, closing the gas valve When the temperature of the Water in the heater rises above a predetermined point.

7 In combination in an instantaneous Water heater having an inlet and an outlet,

a reciprocatory water actuated meansoperdetermined point, asecond spring Weaker than the first spring for opening the valve when the first spring is restrained b the thermostat from acting uponthe tubular stem, a rod extending slidably through the tubular stem and provided with means for engaging the valve and closing it when the rod is in its forward extreme of movement, fiand a third spring stronger than the second extreme of movement, the said Water actuated means and the rod being positioned so that the rod is moved to restrain the third spring and permit the valve to-open under the influenceof the second spring when the outlet from the heater is opened.

In testimony 'whereof I have hereunto s1gned my name in the subscribed witnesses.

FRANK L. OQWADSWORTH.

Witnesses: v i

Ln'rrm A. MYERs,

DOERING BELLINGER.

spring for moving the rod to such forward presence of the two 

